ST. LOUIS (TNS) — The Royals placed starting pitcher Trevor Cahill on the disabled list on Thursday afternoon, one day after he lasted just 2  1/3 innings in an 8-5 loss to the Cardinals at Busch Sta

The club described the injury as “right shoulder impingement syndrome.” Royals manager Ned Yost offered a more casual name for the ailment.

“He’s just got rotator cuff weakness,” Yost said.

The team recalled reliever Kevin McCarthy from Class AAA Omaha to fill Cahill’s roster spot. Rookie Jakob Junis is a likely candidate to return to the majors and start Monday in Oakland when Cahill’s turn in the rotation comes up.

Junis, 24, surrendered one earned in eight innings in a 9-1 victory over the Seattle Mariners on Sunday. He was on the roster as the Royals’ 26th man for a doubleheader and sent back to Omaha following the game. Because of that, he would not need to spend the requisite 10 days in the minors after a demotion.

The injury to Cahill will raise some eyebrows because of the name of his former employer. The veteran right-hander was acquired last month from the San Diego Padres, an organization that was punished for not disclosing medical information during a trade that sent left-handed pitcher Drew Pomeranz to the Boston Red Sox last season.

Padres general manager A.J. Preller was suspended 30 days by Major League Baseball. In a separate incident, the Miami Marlins complained when pitcher Colin Rea was acquired from San Diego last July and exited his first start with elbow soreness. Rea was later returned to the Padres.

On Thursday, Yost indicated that the Royals were comfortable with Cahill’s medical records before executing a deal that also brought relievers Brandon Maurer and Ryan Buchter to the team.

“We knew all this going in,” he said.

In fact, the trip to the disabled list comes on the heels of three disappointing performances. Since being acquired on July 24, Cahill has posted a 8.18 ERA and issued nine walks in 11 innings. He has failed to complete five innings in any outing, and he recorded just seven outs on Wednesday night while allowing three runs on five walks and four hits.

“He’s been pitching through it,” Yost said. “Last night, he just got really fatigued early. He’s just got rotator cuff weakness. It just got fatigued basically after the first inning. Basically, you just take a step back and let it get strong again.”

Cahill’s performance is in stark contrast to his first 11 starts with San Diego, in which he had a 3.69 ERA with 72 strikeouts in 61 innings. Cahill, however, previously battled shoulder issues. In May, he was placed on the 10-day disabled list because of a right shoulder strain.

“The majority of it is just rotator cuff weakness,” Yost said. “His shoulder is pretty structurally sound. He’s got the natural wear and tear of a veteran pitcher.”